This is artist Jamie Martin's Cybernetic Autonomous Remote Barricade police robot, equipped with armor, impulse cannons, and smoke screens. If that sounds like a bad idea, Martin's one step ahead of you; he made this video of it going rogue:

Martin did all of the design, modeling and animation for the C.R.A.B. and imagined this history of its creation:

The advanced robotics technology behind the C.R.A.B.'s artificial intelligence have been secretly developed over the past 12 years as a joint venture between weapons manufacturer Dalton/Stanley and megacorporation Omni Consumer Products.

The results of their historical collaboration has been to produce the most advanced robotic defence system ever constructed, featuring next-generation weaponry and armour protection. The C.R.A.B. is set to pave the way for all future Police and Military automaton technology from here onwards, and will be found on patrol in the public domain very soon.

It sure is a good thing the C.R.A.B. is just a concept, right?! Then again, he did say that its A.I. was developed in secret...[Jamie Martin via io9]